Step 1 Make a paste from the powdered oxygen bleach and water. The exact amounts that you will use will be determined by the amount of grout you need to clean and by the brand of oxygen bleach that you use. The general process is to add small amounts of water until you have a thick mush that looks much like old-fashioned baking soda toothpaste in consistency, although it may be a darker color. Wear your rubber gloves for this entire process.

Step 2 Use the scrub brush to apply a thick layer of paste to the grout. If you want, you can also apply it to the tiles, since it will also remove stains there without hurting the colors and designs. The paste should cover the grout completely, but it does not need to be clumped up in thick lumps on top of the grout. A thin, smooth covering will suffice.

Step 3 Let the paste sit on the colored grout for 30 minutes. This will give the oxygen bleach time to work its way into the pores in the grout and attack the stains at their base. This results in permanent stain removal rather than temporary lightening.

Step 4 Scrub the grout with a moistened scrub brush. The paste will scrub away easily, and the grout beneath will look like new.

Step 5 Clean the area completely. Sponge-rinse the entire area and dry it with the rags. There should be no remnants of the oxygen bleach paste when you are done. Your grout will have retained its original color and now should be totally stain-free. good luck.